Mounting means for electric switch



P. HUTT 2,810,049

MOUNTING MEANS FOR ELECTRIC SWITCH Oct. 15, 1957 Filed Feb. 1, 1956 lllllllli Ji Z3?" W J Philip'Hutt,"Milford, Conn, assignor to General Electric Company, a corporation of New York i- Application February 1, 1956, Serial No. 562,799

' 4'Claims. (Cl. 200-168) The present invention relates to a means for mounting an electric switch on a bushing so that the switch may bein'stalled in the column of a portable lamp.

The great majority of portable lamps in use today are provided with a combined lamp socket and switch either of the turn knob, pull-chain or push-through types which are hidden from view by the lamp shade. There are also many floor lamps where a turn knob switch is separate from the lamp socket, but again it is hidden by the lamp shade. In an attemptto increase the ease of operating portable lamps, switch designs have been conceived for either the base of a lamp or the column of a lamp so that it will be'out from under the lamp shade and clearly in view. The present mounting means was conceived in connection with a novel drum switch which is being claimed in my copending application, Serial No. 562,767, filed simultaneously with this application and assigned to the same assignee. Although my invention of the mounting means was conceived with relation to a particular drum switch, it should be understood that it is not limited to such an application since it would have general utility in the switch art.

If the switch is to be mounted in the column of a portable lamp, lead wires must be brought in through the base of the lamp to be connected to the switch and then carried on up to the lamp socket. Thus, the switch must be hollow so that the lead wires may be hidden within the column of a lamp. Consequently, the main supporting element of the switch is a split bushing of elongated tubular shape having internal threads at each end for joining with the wiring pipes or conduits of the lamp. The switch is to be concentrically arranged over the, bushing so that it may be rotated with respect to'the column of the lamp. However, a problem arises as to how to form shoulders on the bushing to prevent the switch parts from becoming disassembled.

.My invention comprises the use of one or more pairs of longitudinally spaced embossings on the outer surface of the bushing which have inclined portions that lead outwardly from the bushing toward each other so that a washer or other separable shoulder member such as an adapter can be forced over the bushing to engage the embossings, thereby reducing the diameter of the bushing until the washer is confined between one or more pairs of complementary embossings. Finally, when the wiring conduits are threaded into the ends of the bushing, the bushing would no longer be capable of collapsing so that-a highly reliable mounting means for the switch is the result.

The principal object of this invention is to provide a means for mounting an electric switch on a split bushing that is to be connected in the column of a portable lamp.

A further object of this invention is to providea split bushing with one or more separable shoulder members so that an electricswitch may be assembled on the bushmg. r

, A" further object of this invention is to provide a means for'niountingan electric switch on a split bushing we Patent by using separable shoulder members thatare rigidly held in place once the bushing is assembled to the column of a lamp. My invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appendedclaims. i

Figure l is a cross-sectional elevational view of an electric switch supported on a split bushing embodying the novel mounting means of my invention.

Figure 2 is an elevational view of a portion of a col{ umn of a portable lamp showing two' types of separable shoulder members assembled'on the split bushing for supporting an electric switch.

Figure 3 is an exploded view showing in detail the various elements of the switch and its mounting means of Figure 1.

Referring in detail to the drawing, Figure 1 shows a switch mounting means embodying my invention comprising a split metal bushing 10 having a longitudinal split 11 with internal threads 12 formed ineach end for attachment with the wiring conduits of a portable lamp. The switch mechanism generally indicated at 13 is of cylindrical shape so that it may be installed over the bushing and supported thereby. The actual design of the switch mechanism does not form part of the present invention since it is being claimed in my copending appiication filed simultaneously with this application, although it will-be explained briefly with relation to Figure 3 of the drawing. V My invention is primarily concerned with the method of supporting the switch mechanism -13. on the bushing: I propose to use a separable shoulder member such as the washers 14 to prevent the switch mechanism from moving along the bushing once the switch is assembled thereon. Such a result is accomplished by forming pairs of complementary outer embossings 15 on the outer-sur;- facev of the bushing atpoints where itis necessary to hold the washers in place. Thus, there willbe a ring. of such embossings adjacent the topof the bushing as well 'as a similar ring of embossings at the bottomso as to confine the switch mechanism between the-two washers. In actual practice the emboss'ings are struck outof the bushing materialadjacent the sp1it 11 a'sfsee'n .1

in Fig. 3-so that each pair is formed withaspace. therebetween that is substantially equal to the thickness of the washer. At least the endmostiembossingofeach pair. has a tapered back. surface that extends outwardly of the bushing and towardthe other. end toact as a camming surface.

" Thus, itis I a 14 on the bushing, preferably the lowcr one,.so that-the switch mechanism 13 can be installed over thebushing' and seated on this washer with the lead wires16. of the switch extending from the switch mechanism through the bushing for connection with theother conductors ofthe circuit. Then to completelhe. assembly-.ofthe switch, the top washer 14 is thrust. doviznoventhe end, of the bushing so that as. the. washer engages the cam surface of the. embossings, thebushingwill tend-.to close.

so that its diameter will be reduced until the .washersnaps into the space 17 between-.the complementary embossings 15 and be confined rigidly inplace. .,This

type of assembly has provedto be quitev successful and it amounts to a substantial reduction-in the costnof' manufacturing a switch of the type disclosed. 1.

Looking now at Figure '2, another application..lbf.my

invention will be discussed. First,1I will point out 'th 1 elements illustrated" in the figure that ar'e common to those already discussed, namely, {th same f'sp'lit ltl with its threaded J ends 12 the switEh mechanism 13' possible to firstinstall one of the washers.

merely shown in outline and the top washer 14 confined between the embossings 15 on the outer surface of the bushing. In the design of portable lamps there are several possible wiring arrangements where the lead wires of the switeh are either directly connected to the terminals of the lamp socket or connected first to a junction block which is in turn joined to the lead wires from the lamp socket. In a wiring arrangement using a junction block, the block would either be mounted near the lamp socket or, alternately, in the base of the lamp. When the latter method is used, there would be a larger accumulation of lead wires in the wiring conduit below the switch than the, one above the switch. In such case it is necessary to provide an adapter at the bottom of the bushing fog connection with a larger size conduit than is neededat the top of the bushing.

As an eir ample, the wiring conduit 18 in Figure 2 is shown threaded in the top end of the bushing 10, while an adapter 19 is supported on the bottom end of the bushing for threaded engagement with the enlarged conduit 20 that leads, upwardly from the lamp base. It will be understood that this adapter 1? performs the additional function of forming a separable shoulder member for supporting the lower end of the switch mechanism 13. The upper endof the adapter has an enlarged flange 21 that is substantially the same diameter and thickness as the washer 14;. Also, the inner surface of the adapter has a circular groove 22 so that the interior edge 23 of the flange 21 presents the same configuration as the washer 14 for cooperation in the space 17 separating the pair ofcomplementary embossings 15. Thus, the adapter 19 may be installed on the bushing 10 in a similar manner as the washer 14. However, there is one other problem to be solved and that results from the fact that the conduit 201s to be threaded in the end of the adapter 19. which requires that the adapter be prevented from turning. However, the solution is fairly simple in that the lower edge of the bushing 10 is staked by means of a punch at several places around the bushing, and as an additional precaution it is desirable to emboss the adapter 19 inwardly into the split 11 of the bushing.

Now a brief discussion of the details of the switch mechanism will be given with relation to Figure 3 of the drawing. The parts: of the assembly which have already been mentioned are easily recognized as the split bushing 10 with its longitudinal split 11 and threaded ends 12 with the lower and upper washers 14 for mounting in the spaces 17 formed between the pair of complementary embossings 15 onthe outer surface of the bushing. A series of three elongated openings 25 are formed adjacent the lower end of the bushing so that the lead wires 16; of the switch may extend therethrough as best seen in Figure 1. Another advantage of the split bushing 10 is that it may, be fabricated from sheet steel, making it possible, to punch out the openings 25 and chamfer the edges to remove all burrs that might damage the insulation of the wires. This is all done before the bushing is rolled into shape and the threads 12 cut in the ends thereof: The switch mechanism 13 comprises three basic elements, namely, the tubular base 26 molded of a suitable insulated material such as melamine or urea, and a similar molded drum 27 that is telescopically arranged over the base, and, thirdly, an intermediate member 28 comprising :an insulating washer 291 containing a series of V-shaped spring pawls 30 for joining the movable and the fig red contacts of the switch. The base 26 has a hub 31 and a series of ratchet teeth 32 at the base of the hub. Three of these ratchet teeth 32 are replaced by a fixed contact suchas contact 33 connected on the end of the leadwire 16. which also have the form of ratchet teeth. Likewise, inthedrum 27 there is a split metal ring 34. having av series of ratchet teeth opposed to the ratchet teethi 3210f;- the base. for reasons which will, be better, und t pd with reference to my copending application ts ab. a As ar s t e s i h m shan .3 is o cerned, it would perhaps suffice to know that the base 26 is mounted on the bushing 10 against relative rotation by the cooperation of the longitudinally extending grooves 35 on the interior of the base for cooperation with the pairs of embossings 15 on the bushing, while the drum 27 is telescopically arranged over the base, as best seen in Figure l, for relative rotation with respect thereto. Hence, the mounting means of my invention is merely provided on the bushing 10 as separable shoulder members to confine the drum 27 on the base 26, of the switch.

Having described my invention above, it will; be read ily apparent to those skilled in this art that it is both novel in form and ingeniousv in operation while being both low cost and simple to v manufacture. My invention is not limited to the particular embossings illustrated for there are other equivalent means in the art that possibly could be substituted so that when the washers are installed the bushing will collapse temporarily until the washers are clamped, in place.

Modifications of this invention will occur to those skilled in this art; therefore, it is to be understood that this invention is not limited to the particular embodiments disclosed but that it is intended to cover all modifications which are within the true spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A mounting means for an electric switch comprising a longitudinally split cylindrical bushing having internal threads at each end, and at least two pairs of longitudinally spaced outer embossings on the outer surface of the bushing to lie in a transverse plane of the bushing that is nbstantially perpendicular to the longitudinal axis of the bushing, the embossings being near the end of the bushing and adjacent the split with one pair of embossings at either side of the split, the back surface of the endmost embossing of each pair being inclined outwardly from the bushing toward the opposite end, the space between each related pair of embossings forming a clamping section, and a separable shoulder member arranged on the bushing to be confined in the clamping sections of the embossings, and threaded members attached to the ends of the bushing to lock the shoulder member in place by preventing the collapse of the bushing.

2. A mounting means for an electric switch comprising a longitudinally split bushing having at least one pair of longitudinally spaced outer embossings on the outer surface near one end thereof and adjacent the split, and a separable shoulder member comprising a washer arranged on the bushing so that it is confined between the said embossings, and a member fastened to the said end of the bushing for preventing the reduction of the diameter of the bushing.

3. A method of assembling a hollow cylindrical switch on a longitudinally split bushing comprising the steps of mounting the switch on the bushing and then forcing a washer over one end of the bushing until it engages a tapered outer embossment on the outer surface of the bushing adjacent the split so that further movement of the washer will collapse the bushing until the washer is confined between the first embossment and a complementary embossment that is longitudinally spaced from the first by a distance that is substantially equal to the thickness ofthe washer.

4. A method of assembling a cylindrical adapter over a longitudinally split bushing comprising the steps of" inserting the adapter over the bushing until an inner circular lip of the adapter strikes an outer embossment on the outer surface of the bushing near one end thereof and adjacent the split, further movement of the adapter onto the bushing tending to, collapse the. bushing until the lip rides over the embossment and is confined between the first embossment and a complementary embossment that is longitudinally spaced from the first, and then forcing a portion of the adapter into the split of the bushing so that the bushing may not be collapsed to decrease the holding power of the embossment with the adapter.

References Cited in the file of this patent UNITED STATES PATENTS Pfleager Feb. 25, 1919 Tucker Nov, 14, 1939 Booth Dec. 7, 1954 Steiner -5 Feb. 22, 1955 

